change search.php to buscar.php

Dear friends, I know how to turn the page “search.php” default wordpress? as everyone knows can do a search URL as follows: http://tudominio.com/search/texto+a+buscar

need to change something like this: http://tudominio.com/buscar/texto+a+buscar

where “/ search / ” can be any word.

I hope you can help.